I am creating an UCMA client application with UserEndpoint. When connected to our organization's Lync server inside internal domain, my UCMA application is able to establish connection with server. But when trying to connect through external network, I am getting the following error while initializing ClientPlatformSettings with Tls:
An exception of type 'Microsoft.Rtc.Signaling.RealTimeException' occurred in mscorlib.dll but was not handled in user code
Additional information: An error occurred while retrieving the local host name.
The Skype for Business client is able to connect the organization's Lync server from any network. So I guess the Lync server is autodiscovery enabled.
Since I am creating UCMA client application, I dont think we need to make it as trusted application and need to install any certificates (am I correct?)
Why I am getting error when trying to connect from external networks?
Connecting as a client endpoint from an external network requires going via the enterprise edge server, rather than directly to a user pool. Make sure that remote user client access is enabled in CMS, and also that a supported authentication protocol is available. S4 trace logs will tell you where your app is trying to connect to.